The Environmental Protection Agency (EPA or Agency) is proposing three actions pursuant to section 181(b)(2) of the Clean Air Act (CAA) related to the attainment date for 31 areas classified as ``Marginal'' nonattainment for the 2015 ozone National Ambient Air Quality Standards (NAAQS). First, the Agency is proposing to determine that six areas attained the standard by the applicable August 3, 2021, attainment date. Second, the Agency is proposing to grant a 1-year attainment date extension for the Uinta Basin, Utah, nonattainment area.

With this direct final rule, the Environmental Protection Agency (EPA or the ``Agency'') is promulgating approval of South Dakota's submittal requesting that EPA recognize the merger of South Dakota's Department of Agriculture (DOA) with the Department of Environment and Natural Resources (DENR) to form the new Department of Agriculture and Natural Resources (DANR) and incorporate corresponding non-substantive revisions to the South Dakota Codified Law (SDCL) and the Administrative Rules of South Dakota (ARSD) into South Dakota's Implementation Plan.

The Environmental Protection Agency (EPA) finds that the Chicago-Naperville, IL-IN-WI area (Chicago area) is attaining the 2008 ozone National Ambient Air Quality Standard (NAAQS or standard) and, in response to a request from the Wisconsin Department of Natural Resources (Wisconsin or the State), is redesignating the Wisconsin portion of the area to attainment for the 2008 ozone NAAQS, because the State has met the statutory requirements for redesignation under the Clean Air Act (CAA).

The Environmental Protection Agency (EPA) is approving revisions to the State Implementation Plan (SIP) for Indiana and revisions to the operating permit program for Ohio. The revisions incorporate changes to the definition of ``chemical process plants'' under Indiana's Prevention of Significant Deterioration (PSD) regulations and under Ohio's operating permit program. EPA also provided an opportunity for public comment on similar changes to the definition of ``major stationary source'' in Ohio's PSD regulations that were approved into the SIP on October 28, 2014.